CYNIPID^E. 209 



(not being elbowed) thirteen to sixteen-jointed antennae, the 

 labial palpi being from two to four-jointed, and the maxil- 

 lary palpi from four to six-jointed. The maxillary lobes are 

 broad and membranous, while the ligula is fleshy, and either 

 rounded or square at the end. There is a complete costal cell, 

 while the subcostal cells are incomplete. The egg is of large 

 size, and increases in size as the embryo becomes more devel- 

 oped. The larva is a short, thick, fleshy, footless grub, with 

 the segments of the body rather convex. When hatched they 

 immediately attack the interior of the gall, which has already 

 formed around them. Many species transform within the gall, 

 while others enter the earth and there become pupae. 



It is well known that of many gall-flies the males have never 

 been discovered. "Hartig says that he examined at least 

 15,000 specimens of the genus Cynips, as limited by him, with- 

 out ever discovering a male. To the same purpose he collected 

 about 28,000 galls of Cynips divisa, and reared 9,000 to 10,000 

 Cynips from them ; all were females. Of G. folii, likewise, he 

 had thousands of specimens of the female sex without a single 

 male." (Osten Sacken.) Siebold supposes in such cases that 

 there is a true parthenogenesis, which accounts for the immense 

 number of females. 



Mr. B. D. Walsh has discovered (American Entomologist, 

 ii, p. 330) that Gynips quercus-aciculata O. Sack., which pro- 

 duces a large gall in the autumn upon the black oak, in the 

 spring of the year succeeding lays eggs which produce galls 

 disclosing Cynips quercus-spongifica O. Sack. He proved this 

 by colonizing certain trees with a number of individuals of 

 G. quercus-aciculata, and finding the next spring that the eggs 

 laid by them produced G. quercus-spongifica. The autumn 

 brood of Cynips consists entirely of agamous females, while 

 the vernal brood consists of both males and females, and Mi\ 

 Walsh declares after several experiments that " the agamous 

 autumnal female form of this Cynips (G. q. aciculata) sooner 

 or later reproduces the bisexual vernal form, and is thus " a 

 mere dimorphous female form" of G. q. spongiftca. 



abdomen of Cynips, showing the relations of segments 7-8, the sternal portion of 

 the eighth segment being obsolete ; sp, the single pair of abdominal spiracles ; VI, 

 terminal ventral piece, from which the sheaths (s s) and the ovipositor (o) take 

 their origin ; it is strongly attached at m to the tergites of the sixth and seventh 

 rings; o, ovipositor; .<?, s its sheaths; a, an appendage to v, the terminal sternite. 

 From Walsh. 



H 



